Shaft-coupling.



2 SHEETS-SHEET 1.

No. 789,222. PATENTED MAY 9, 1905. L. 1). LOVEKIN.

SHAFT COUPLING.

APPLICATION FILED NOV. 10,1904.

2 SHEETS-411E111 2.

F/G. a

4/2682 Awe/17W 7/2 M. M

ll/2 A2 NITED STATES Patented May 9, 1905.

PATENT FFICE.

SHAFT-COUPLING.

SPECIFICATION forming part of Letters Patent No. 789,222, dated May 9,1905.

Application filed November 10, 1904. Serial No. 232,198.

To all whom it may concern:

Be it known that I, LUTHER D. LOVEKIN, of the city and county ofPhiladelphia and State of Pennsylvania, have invented an Improvement inShaft-Couplings, of which the following is a specification.

My invention has reference to shaft-couplings; and it consists ofcertain improvements which are fully set forth in the followingspecification and shown in the accompanying drawings, which form a partthereof.

My invention embodies improvements upon the type of shaft-coupling setout in Letters Patent No. 636,411., granted to me on November 7, 1899.In that construction the propeller-shaft was coupled with the line-shaftby means of a coupling comprising a flange on the line-shaft, a collarbolted to the flange and keyed to the propeller-shaft, and a splitthrust-ring fitted into a groove near the end of the propeller-shaft andclamped between the flange of the line-shaft and the collar. Theobjection to this was that the torsional strains were transmittedthrough keys located wholly on one side of the thrust-ring and requiredto pass through the collar and bolts of the coupling, which involved aweakness, to overcome which the present invention is designed.

In my present improvement the coupling is so designed as to utilize theentire length of the same for keys which transmit the strains from theengine or line shaft to the propeller. The thrust-groove in thepropeller-shaft is located at a point from the end predetermined by themoment of resistance of the shaft at its reduced section, and the amountof work transmitted through that portion of the key between the grooveand the end of the shaft is made proportional to the strength of thereduced portion of the shaft at said groove. Furthermore, the portion ofthe key beyond the thrust-ring need only be of suflicient length totransmit the torsion required to make up the full torsional strength ofthe adjoining or line shaft. In the case of propeller-shafts forsteamships this line-shaft is always made of less diameter than thepropeller-shaft, and consequently I am enabled to design the coupling inthe manner described without adding any additional metal to the insideof the grooved propeller-shaft, thereby simplifying the construction andreducing the weight of the coupling as a whole. The coupling-bolts aredesigned so as to transmit the entire shearing load at the joint of thecoupling adjacent to the line-shaft and to transmitsuch proportions ofthe total load in the coupling beyond the thrust-ring as may be requiredby that portion of the key beyond the said ring. In this constructionthe bolts employed have a larger sectional area adjacent to theline-shaft than at the distant end adjacent to the thrustring, and thethreads of the bolts need only be of sufficient strength to withstandthe thrust of the propeller when going astern and which is usually verysmall as compared to the actual strength of the shaft proper. Thethrust-rings are made in small sections fitting into the thrust-grooveof the propeller-shaft between the keys only and are provided withliberal bearing-surfaces for taking the thrust when the vessel is goingastern.

My improved coupling combines the features of extreme simplicity and thegreatest possible reduction in weight consistent with strength.

My invention will be better understood. by reference to the drawings, inwhich Figure 1 is a longitudinal sectional elevation of a couplingembodying my improvement on line a :1: of Fig. 2. Fig. 2 is acrosssection of same on line 1 y of Fig. l. 3 is a sectional elevationof a modification, and

Fig. 4 is a perspective view of one of the secvided with keyways E, ofwhich four are shown, and said keyways extend from the end I DO of theshaft throughout the whole length of the coupling and are fitted withkeys F, as

shown. Interposed between these keys and fitting the groove B of thepropeller-shaft are the sections G of the thrust-ring, said sectionsterminating adjacent to the keys F.

lnclosing the end of the shaft A up to the point of the thrust-ringsections G is a coupling-ring H, which tightly fits the shaft and haskeyways I for the keys F and a groove J for the sections of thrust-ring.It will be seen from this that the coupling-ring is directly connectedwith the end of the shaft beyond the thrust-rings through the keys, andthe length of these keys is made proportional to the strength of theshaft on the section of the thrust-groove B and would be longer orshorter, accordingly as the strength of this portion of the shaft wasdecreased or increased to suit the requirements of the work.

In practice the end of the shaft A is made with a very slight taper,approximating onesixteenth of an inch per foot, and the ring H is madeto correspond and is pressed upon the end of the shaft to make a tightfit. The collar K of the coupling encircles the shaft A with a tightfit, as is the case of the ring H, and is bolted up tightly against thering by the bolts L. This collar is provided with keyslots M to receivethose portions of the keys F which are beyond the thrust-ring sections Gand is designed to perform the double duty of transmitting power fromthe line-shaft to the propeller-shaft and also to take the end thrust ofthe propeller-shaft through the sections of the thrust-ring in goingastern.

While I have the juncture of the collar K with the ring H of thecoupling adjacent to the rear surface of the thrust-ring sections, suchjuncture may, if desired, be at the forward surface of thesering-sections or at any point intermediate of said surfaces, as will bereadily understood, as it is immaterial whether the groove J for thesaid thrust-ring sections is formed in the part H or part K or partly ineach, since the operation of the structure would be the same.

The bolts L for uniting the flange D of the line-shaft to the ring H andcollar K of the coupling are made tapering, so as to be much strongeradjacent to the end of the flange D of the line-shaft than at the pointof juncture between the ring H and collar K, since the cross-section ofthese bolts at the end of the ring adjacent to the flange D must be ofsufficient area to transmit all of the shearing load which may beproduced by the power transmitted through the keys F between the flangeD and the thrust-ring sections G, to-

gether with the strains transmitted from the shaft, through the portionsof the key connecting with the collar K beyond the thrustbe sufiicientto transmit the shearing load which would be due to the strainstransmitted through the collar K and that portion of the keysFincontacttherewith. The screw threads or nuts N of these bolts must besufficiently strong to resist the end thrust of the shaft on the collarK in going astern. It is evident that, while the tapering form of thebolt is the most satisfactory construction, I do not confine myself toany particular shape of the bolt, so long as the cross-section thereofat one end of the ring H is greater than the cross-section at the otherend, to secure the results pointed out above. It is also evident that,while the diameter of the bolts must be sufiiciently large at the end ofthe ring adjacent to the lineshaft to transmit the entire shearing load,it is only necessary to my invention that the cross-sections of thebolts at the other end of the ring H shall be at least large enough totransmit the shearing load at this point, and the object of making thebolt small at this point is to reduce weight by enabling the di ameterof the ring H and collar K to be kept within the smallest possiblelimits.

The tapered end of the propeller-shaft is clearly shown in Fig. 3, andin this figure the recess J for the thrust-ring is shown in thecoupling-collar K instead of the coupling-ring H, as hereinbeforereferred to, as these modifications or either of them may be employed inplace of what is shown in Fig. 1.

While my invention is especially designed for propeller-shafts and theparticular illustration is that which is employed in the battle-ships ofthe United States N'avy of the Iicmsas class, the improvements areapplicable to any line of shafting where astrong and compact coupling isrequired.

The details of construction may be modified without departing from theprinciplesof construction involved in my invention, and I therefore donot limit myself to the minor details.

Having now described my invention, what I claim as new, and desire tosecure by Letters Patent, is j .1. In a shaft-coupling, the combinationof one shaft provided on the end with a flange, a second shaft providedwith a circumferential groove near its end and one or more continuouskey-grooves in the surface of the shaft extending from its end acrossthe circumferential groove to a distance beyond the same, one or morecontinuous keys fitted to said key-grooves, a thrust-ring made in two ormore parts fitted to the circumferential groove intermediate of thekeys, a coupling-ring inclosing the end of the second-mentioned shaftand receiving those portions of the keys between the thrust-ring andfirst-mentioned shaft, a collar inclosing the shaft and located at theend of the coupling-ring distant from the first-mentioned shaft andprovided with grooves to receive those portions of the keys beyond thethrust-ring, and a series of bolts for clamping the first-mentionedshaft the coupling-ring and the coupling collar together.

2. In a shaft-coupling, the combination of one shaft provided on the endWith a flange, a second shaft provided With a circumferential groovenear its end and one or more continuous key-grooves in the surface ofthe shaft extending from its end across the circumferential groove to adistance beyond the same, one or more continuous keys fitted to saidkey-grooves, a thrust-ring made in tWo or more parts fitted to thecircumferential groove intermediate of the keys, a coupling-ringinclosing the end of the second-mentioned shaft and receiving thoseportions of the keys between the thrust ring and first mentioned shaft,a collar inclosing the shaft and located at the end of the coupling-ringdistant from the first-mentioned shaft and provided With grooves toreceive those portions of the keys beyond the thrust-ring, and a seriesof bolts for clamping the first-mentioned shaft, the coupling ring, andthe couplingcollar together and in Which the cross-section of the boltsat the juncture of the coupling-ring and flange of the first-mentionedshaft is greater than the cross-section ofthe same bolts at the junctureof the coupling-ring and couplingcollar.

3. In a sl1aft-cou1: ling, the combination of one shaft provided on theend With a flange, a second shaft provided With a circumferential groovenear its end and one or more continuous key-grooves in the surface ofthe shaft extending from its end across the circumferential groove to adistance beyond the same, one or more continuous keys fitted to saidkey-grooves, a thrust-ring made in tWo or more parts fitted to thecircumferential groove intermediate of the keys, a coupling-ringinclosing the end of the second-mentioned shaft and receiving thoseportions of the keys between the thrustring and first-mentioned shaft, acollar inclosing the shaft and located at the end of the coupling-ringdistant from the first-mentioned shaft and provided With grooves toreceive those portions of the keys beyond the thrust-ring, and a seriesof tapered bolts for clamping the first-mentioned shaft thecoupling-ring and the coupling-collar together and in which the smallerends of the bolts are located in the coupling-collar.

4. The combination of ashaft, asecond shaft having a circumferentialgroove at a distance from its end and one or more longitudinalkeygrooves extending from the end of the shaft to the circumferentialgroove, keys arranged in the key-grooves, a thrust-ring in sectionsarranged Within the circumferential groove of the second shaft, acoupling-ring inclosing the shaft and having key-grooves for the keys, acollar inclosing the shaft and fitted against the surface of thethrust-ring sections, and clamping-bolts for connecting thefirst-mentioned shaft with the coupling ring and collar.

5. The combination of a shaft, asecond shaft having a circumferentialgroove at a distance from its end and one or more longitudinalkeygrooves extending from the end of the shaft to the circumferentialgroove, keys arranged in the key-grooves and extending across thecircumferential thrust-groove, a thrust-ring in sections arranged Withinthe circumferential groove of the second shaft and intermediate of thekeys, a coupling-ring inclosing the shaft and having key-grooves for thekeys, a collar inclosing the shaft and fitted against the surface of thethrust-ring sections, and clamping-bolts for connecting thefirst-mentioned shaft With the coupling ring and collar.

6. In a shaft-coupling, the combination of one shaft provided on the endWith a flange, a second shaft having its end tapered and provided at adistance from its end With a circumferential groove and one or morecontinuous key-grooves in the surface of the shaft extending from itsend across the circumferential groove to a distance beyond the same, oneor more continuous keys fitted to said keygrooves, a thrust-ring made intWo or more parts fitted to the circumferential groove intermediate ofthe keys, a coupling-ring having a tapered hole inclosing the end of thesecondmentioned shaft and receiving that portion of the keys betweenthethrust-ring and first-mentioned shaft, a collar inclosing the shaftand located at the end of the coupling-ring distant from thefirst-mentioned shaft and provided With grooves to receive that portionof the keys beyond the thrust-ring, and a series of bolts for clampingthe first-mentioned shaft the coupling-ring and the coupling-collartogether.

In testimony of Which invention I hereunto set my hand.

LUTHER D. LOVEKIN.

Witnesses:

R. M. KELLY, M. J. EYRE.

